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| United States Patent |
6,241,933
|
|
Koll
, et al.
|
June 5, 2001
|
Process for the treatment of cellulosic moulded bodies
Abstract
The invention relates to a process for the treatment of cellulosic moulded
bodies which are formed from a solution of cellulose in an aqueous
tertiary amine oxide, particularly fibers, whereby the moulded bodies are
brought into contact with an aqueous solution of a textile auxiliary agent
which bears two reactive groups in the alkaline milieu. The invention is
characterised in that as the textile auxiliary agent, a compound of
formula
##STR1##
whereby X is halogen, R.dbd.H or an ionic residue and n=0 or 1,
respectively a salt of this compound is used. The invention also relates
to the use of compounds of this formula to reduce the tendency to
fibrillate and to increase the UV absorption of solvent-spun fibers.
| Inventors:
|
Koll; Berndt (Lenzing, AT);
Bartsch; Peter (Nussdorf, AT);
Mulleder; Eduard (Linz, AT)
|
| Assignee:
|
Lenzing Aktiengesellschaft (Lenzing, AT)
|
| Appl. No.:
|
333837 |
| Filed:
|
June 15, 1999 |
Foreign Application Priority Data
| Current U.S. Class: |
264/340; 8/190; 264/345 |
| Intern'l Class: |
D02J 013/00; D06M 013/358 |
| Field of Search: |
264/340,345
8/190
|
References Cited
U.S. Patent Documents
| 3074814 | Jan., 1963 | Sause et al.
| |
| 3124414 | Mar., 1964 | Dolmetsch et al.
| |
| 4246221 | Jan., 1981 | McCorsley, III.
| |
| 6033443 | Mar., 2000 | Aeschlimann.
| |
| Foreign Patent Documents |
| 1085492 | Jul., 1960 | DE.
| |
| 1141612 | Dec., 1962 | DE.
| |
| 1141973 | Jan., 1963 | DE.
| |
| 1148222 | May., 1963 | DE.
| |
| 0538977 | Apr., 1993 | EP.
| |
| 0553070 | Jul., 1993 | EP.
| |
| 0616071 | Sep., 1994 | EP.
| |
| 1243816 | Jan., 1959 | FR.
| |
| 880624 | Oct., 1961 | GB.
| |
| 896814 | May., 1962 | GB.
| |
| 9319230 | Sep., 1993 | WO.
| |
| 9749856 | Dec., 1997 | WO.
| |
Other References
Harold Lomas, Improvement in the hand of fibrous materials and sheets,
Chemical Abstracts vol. 55 pp. 19263-19264 (1961).
Application for U.S. Ser. No. 09/289,317, filed Apr. 9, 1999.
Application for U.S. Ser. No. 09/633,409, filed Sep. 15, 2000.
Application for U.S. Ser. No. 09/289,316, filed Apr. 9, 1999.
|
Primary Examiner: Tentoni; Leo B.
Attorney, Agent or Firm: Baker Botts L.L.P.
Parent Case Text
This is a continuation of copending application Ser. No. PCT/AT98/00236
filed Oct. 7, 1998 which is incorporated by reference herein.
Claims
What is claimed is:
1. Process for the treatment of cellulosic moulded bodies shaped from a
solution of cellulose in an aqueous tertiary amine oxide comprising:
providing moulded bodies
providing an aqueous solution of a textile auxiliary agent, which carries
two reactive groups wherein the textile auxiliary agent is selected from
the group consisting of a compound having the formula
##STR5##
whereby X is halogen, R.dbd.H or an ionic residue and n=0 or 1, and a salt
of the compound
contacting the moulded bodies with the aqueous solution of the textile
auxiliary agent in an alkaline medium.
2. Process according to claim 1 wherein the textile auxiliary agent is a
metallic salt of the compound.
3. Process according to claim 1 wherein n=1 and R is an anionic residue and
wherein the textile auxiliary agent is a metallic salt.
4. Process according to any one of claims 1, 2 or 3 wherein the cellulosic
moulded bodies are never dried fibres.
5. Process according to any one of claims 1, 2 or 3 wherein the pH value of
the aqueous solution of the textile auxiliary agent is from 12 to 14 when
being brought into contact with the moulded bodies.
6. Process according to any one of claims 1, 2 or 3 wherein the moulded
bodies are subjected to heat treatment during contact with the aqueous
solution of the textile auxiliary agent.
7. Process according to claim 4 wherein the pH value of the aqueous
solution of the textile auxiliary agent is from 12 to 14 when being
brought into contact with the moulded bodies.
8. Process according to claim 2 wherein n=0.
9. Process according to claim 2 wherein n=1.
Description
The invention relates to a process for the treatment of cellulosic moulded
bodies whereby the moulded bodies are contacted with an aqueous solution
of a textile agent having two reactive groups in alkaline medium.
BACKGROUND OF THE INVENTION
In the last few decades intensive efforts were undertaken to produce
alternative environmentally-friendly processes as a result of the
environmental problems associated with the well-known viscose process. One
of the most interesting things to take shape in the recent past was the
possibility to dissolve cellulose in an organic solvent without the
formation of a derivative and to extrude moulded bodies from this
solution. Fibres spun from solutions of this kind were given the generic
name of Lyocell by BISFA (The International Bureau for the Standardization
of Man-Made Fibres) whereby a mixture of an organic chemical and water is
meant by an organic solvent. Moreover, fibres of this kind are known as
"solvent spun fibres".
It has turned out that a mixture of a tertiary amine oxide and water is
particularly well suited as the organic solvent for the production of
Lyocell fibres respectively other moulded bodies
N-methyl-morpholine-N-oxide (NMMO) is thereby principally used as the
amine oxide. Other suitable amine oxides are disclosed in EP-A 0 553 070.
Processes for the production of cellulosic moulded bodies from a solution
of cellulose in a mixture of NMMO and water are for example disclosed in
U.S. Patent Ser. No. 4,246,221 or PCT-WO 93/19230. In this respect the
cellulose is precipitated from the solution into an aqueous precipitation
bath. Fibres manufactured in this way are characterised by a high fibre
tenacity in a conditioned and wet state, a high wet modulus and a high
loop strength.
One special property of these fibres is the high propensity to fibrillate,
particularly when put under strain in a wet state, such as happens for
example during the washing process. Whilst this property is perfectly
desirable for certain fibre applications and produces interesting effects,
the workability for other purposes, such as textiles for example, which
should be wash-resistant, is reduced.
Thus, no effort was spared to reduce the fibrillation behaviour with
various measures.
Numerous publications deal in particular with the possibility to reduce the
tendency to fibrillate of the fibres by treating these with substances
which have a cross-linking effect on cellulose.
According to EP-A-0 538 977 the fibres, which can be either freshly spun or
already dried, are treated in an alkaline milieu with an aqueous system
which contains a chemical reagent with 2 to 6 functional groups which can
react with cellulose. In EP-A-0 538 977 derivatives of cyanuric chloride,
and substituted dichlortriazines in particular, are named as suitable
substances. Moreover, addition products of cyanuric chloride and
poly(ethylene glycol) monomethylether are used.
From EP-A-0 616 071 it is known that fibre materials containing cellulose,
such as textiles for example, should be treated amongst other things with
metallic salts of partial hydrolyzates of cyanuric chloride to give the
textiles crease resistant and easy care properties. The use of substances
of this kind to treat solvent spun fibres is not, however, mentioned.
In relation to the reduction of the tendency to fibrillate of cellulosic
moulded bodies, which are shaped from a solution of cellulose in tertiary
amine oxides, no publication exists to date despite numerous efforts in
this field which describes the use of multifunctional textile agents the
effect of which justifies the, in the main, high price of these
substances.
SUMMARY OF THE INVENTION
Thus it is the task of this invention to make a process available for the
treatment of cellulosic moulded bodies, which are shaped from solutions of
cellulose in aqueous tertiary amine oxides, using multifunctional textile
auxiliary agents, which leads to the efficient improvement of the
properties of the moulded bodies as a result of using favourably priced
treating substances and, in the case of fibres, of the tendency to
fibrillate in particular.
This task is resolved by a process in accordance with the first part of
claim 1 which is characterised in that a compound of the formula
##STR2##
whereby X is halogen, R.dbd.H or an ionic residue and n=0 or 1,
respectively a salt of this compound is used as the textile auxiliary
agent. As a halogen residue X chlorine should be given preference.
Surprisingly it was shown that the textile agents used in accordance with
the invention, which are relatively favourably priced, have just as great
an effect or even produce a greater improvement in the properties of the
moulded bodies treated as for example the substances known from EP-A 0 538
977 which are manufactured in a laborious manner. Thus it is possible to
solve for example the problem of the tendency to fibrillate of
solvent-spun fibres in an economic way.
In comparison to the addition products of cyanuric chloride and non-ionic
residues as described in EP-A 0 538 977 the compounds according to the
invention are present in ionic form in the aqueous solution in the
alkaline milieu.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferably a salt, particularly a metallic salt of a compound in accordance
with formula (I), in which n=0, i.e. a salt of 2,4-dichloro-6-hydroxy
1.3.5-triazine, is used. Sodium, potassium or lithium salt are preferably
used as the metallic salt.
It is, however, also possible to use 2,4dichloro-6-hydroxy 1.3.5-triazine
as such whereby the ionic form is formed in the alkaline medium of the
treatment of the moulded body.
Preferably the residues R are anionic residues, e.g. --SO.sub.3 or
--C.sub.1 -C.sub.6 -alkyl--SO.sub.3 or CO.sub.2 or--C.sub.1 -C.sub.6
-alkyl--CO.sub.2. The residues R can, however, also be cationic. Residues
R with e.g. --C.sub.1-C.sub.6 -alkyl--N.sup.+ (C.sub.1 -C.sub.4
-alkyl).sub.3 are given preference.
In one preferred embodiment of the invention the treated cellulosic moulded
bodies are never dried fibres. Solvent-spun fibres in their state before
the first drying are designated as "never dried" fibres. It has been shown
that the use of compounds of the formula (I) on never dried fibres in
particular produces a considerable reduction in the tendency to
fibrillate.
Moreover, the use of compounds of formula (I) on already dried solvent-spun
fibres or textiles made of these, e.g. fabrics, warp-knitted fabrics or
knitted fabrics, produces excellent results.
The pH value of the aqueous solution of the textile auxiliary agent
preferably equals 12 to 14 when it is brought into contact with the
moulded bodies.
In another preferred embodiment of the invention the pH value of the
aqueous solution of the textile auxiliary agent is only held in a weak
alkaline range from 7 to 9, e.g. from 7,5 to 8,5 and preferably from 8 to
9 when bringing into contact with the moulded bodies. Since the two
reactive halogen substituents of the compounds according to formula (I)
have difference reactivities, first of all a reaction of the first
reactive group of the textile auxiliary agent takes place with the
cellulose. The moulded bodies are then pressed and brought into contact
with an alkaline aqueous solution with a pH value of 11 to 14, e.g. a pH
value of 13. The reaction of the second reactive group of the textile
auxiliary agent thereby takes place with the cellulose. This embodiment of
the invention is described in the following as the "two-bath" process.
The advantage of this preferred embodiment of the invention is that
hydrolysis of the substance in accordance with formula (I) can be put last
with only weak alkaline pH values and fewer hydrolysis losses have to be
taken into account. This contributes to the economic efficiency of the
process.
In a preferred embodiment of the invention the moulded bodies are submitted
to heat treatment during or after the bringing into contact with the
aqueous solution of the textile auxiliary agent. In the case of the two
bath process the heat treatment can take place during and/or after being
brought into contact with the weak alkaline solution of the textile
auxiliary agent as well as after the bringing into contact of the pressed
moulded bodies with the stronger alkaline aqueous solution. Satisfactory
results are also achieved when a heat treatment only takes place after the
bringing into contact of the moulded bodies with the stronger alkaline
aqueous solution. Thus the step by step reaction of both reactive groups
of the textile auxiliary agent can be purposely controlled by the
respective use of the heat treatment.
The invention also relates to the use of a compound of the formula
##STR3##
whereby X is halogen, R.dbd.H or an ionic residue and n=0 or 1,
respectively of a salt of this compound to reduce the fibrillation
tendency of solvent-spun cellulosic fibres.
Moreover, surprisingly it was found that compounds of formula (I) result in
an increase in the UV absorption of moulded bodies from solutions of
cellulose in aqueous solutions of tertiary amine oxides.
The modification of textiles to increase sun protection efficiency with
certain substances designated as UV absorbers is well known (e.g.
Textilveredelung 31 (1996) 11/12, 227-234). UV absorbers of this kind
reduce the remission respectively the transmission of UV radiation by the
textile. The UV absorbers must be carefully selected depending upon the
fibre material. It has now turned out that the compounds of formula (I)
work as excellent UV absorbers when using solvent-spun fibres or textiles.
The invention thus also relates to the use of a compound of the formula
##STR4##
whereby X is halogen, R.dbd.H or an ionic residue and n=0 or 1,
respectively of a salt of this compound to increase the UV absorption of
solvent-spun cellulosic fibres.
Thus the use of one sole substance when treating solvent-spun fibres can
have two desired effects, namely the reduction of the fibrillation
tendency and an increase in UV absorption. A double effect of this kind
was until now not known according to state of the art.
EXAMPLES
Methods of analysis:
Determining the rate of fibrillation:
The rubbing of the fibres against one another during washing procedures
respectively with regard to finishing processes in a wet state is
simulated by the test which follows: 8 fibres are placed with 4 ml of
water in a 20 ml sample bottle and shaken for three hours in a laboratory
shaking device of the type R0-10 from Messrs. Gerhardt, Bonn (Germany) at
level 12. The fibrillation behaviour of the fibres is then assessed under
the microscope by counting the number of fibrils for each 0.267 mm of
fibre length and is indicated in terms of a fibrillation rating of 0 (no
fibrils) to 6 (pronounced fibrillation).
Determining the wet abrasion value:
Twenty fibres with a length of 40 mm are placed on a metal roll with a
thickness of 1 cm and weighed down with a pre-tensing weight which depends
upon the decitex of the fibres. The roll is covered with a viscose
filament yarn stocking and is continuously moistened. The roll is turned
at a speed of 500 rotations per minute during measuring and at the same
time it is turned diagonal to the fibre axis backwards and forwards
whereby a pendulum movement of approximately 1 cm takes place.
The number of revolutions is measured, until the fibres are worn through.
The mean value of the abrasion cycles of 20 fibres is taken as the
measured value. The higher the number of revolutions, until the fibres are
worn through, the better the fibrillation behaviour of the fibres.
Example 1
A dyed knitted fabric of solvent-spun fibres was brought into contact with
a liquor ratio of 1:30 with an aqueous solution containing 20 g/l sodium
salt of 2,4-dichloro-6-hydroxy 1.3.5-triazine, 20 g/l NaoH and 1 g/l
Leonil SR (wetting agent, manufacturers: Messrs.Hoechst). The solution had
a pH value of 13. The knitted fabric was impregnated with the solution for
five minutes then the excess solution was pressed off with a padder at 1
bar and heat treated with steam for 5 minutes at 100.degree. C. The
knitted fabric was then repeatedly washed with a 2% acetic acid and water
and then dried.
Individual fibres from the knitted fabric were prepared and submitted to a
wet abrasion test according to the instruction given above. The mean value
from the tests equalled 470 revolutions. This complies with a reduction in
fibrillation tendency of approximately 75% compared to an untreated fibre.
Example 2
An undyed knitted fabric of solvent-spun fibres was treated as described in
example 1 and submitted to a wet abrasion test. The mean value from these
tests equalled 620 revolutions.
Example 3
Never dried solvent-spun cellulose fibres produced according to the process
of PCT-WO 93/19230 with a titre of 3.3 dtex were impregnated in a liquor
ratio of 1:25 with a solution containing 30 g/l sodium salt of
2,4-dichloro-6-hydroxy 1.3.5-triazine, 20 g/l NaOH and 30 g/l Na.sub.2
SO.sub.4 for five minutes at room temperature. The solution had a pH value
of 13. The fibres were subsequently heat treated for ten minutes at
110.degree. C. with steam, washed and dried. The fibrillation rate was
measured in the fibres in accordance with the instruction given above.
After three hours of shaking the fibres displayed on average 9 fibrils per
0.267 mm and a fibrillation value of 2.75. Compared to this fibres not
treated with the textile auxiliary agent revealed on average 12 fibrils
for each 0.276 mm after three hours of shaking and a fibrillation value of
4. After 9 hours of shaking in the tester an analogous property was
revealed.
In the abrasion test the treated fibres revealed a mean value of 125
revolutions whilst untreated fibres had a mean value of 13 revolutions.
Example 4
Never dried solvent-spun fibres produced according to the process of PCT-WO
93/19230 with a titre of 1.3 dtex were impregnated with a liquor ratio of
1:10 with a solution containing 30 g/l of sodium salt of 2,4
dichloro-6-hydroxy 1.3.5-triazine and 16 g/l NaOH (pH value of solution:
13) for two minutes at 20.degree. C. The fibres were then heat treated for
one minute with steam at 110.degree. C., washed and dried. Subsequent
abrasion tests were carried out on the fibres. The mean value of the wet
abrasion test equalled 702 revolutions.
Example 5
Two Bath Process
Never dried solvent-spun fibres with a titre of 1.3 dtex were impregnated
with an aqueous solution containing 30 g/l sodium salt of 2,4
dichloro-6-hydroxy 1.3.5-triazine with a liquor ratio for two minutes at
20.degree. C. The aqueous solution revealed a pH value of approximately 8.
Following impregnation the fibres were pressed, brought into contact with
an aqueous solution containing 16 g/l NaOH (pH value of approximately 13),
pressed, heat treated for two minutes at 110.degree. C. with steam, washed
and dried.
The wet abrasion test for fibres treated in this way produced a value of
270 revolutions. This complies with a reduction in the fibrillation
tendency by approx. 50% compared to an untreated fibre.
Example 6
The remission of UV radiation was measured in solvent-spun fibres treated
according to example 3 respectively example 4. In all cases a clear
reduction in the remission value became apparent compared to untreated
solvent-spun fibres. The scale of the no more remitted and thus absorbed
share of UV radiation equals approx. 40%.
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